前台：

ajax:

$(document).ready(function(){

$("#email").blur(function(){

$("#email").css("background-color","#D6D6FF");

$.ajax({type:"post",url:"check_email.do",data:{‘email‘:$("#email").val()},

success:function(data){

if(data==2){

$("#content").html("

邮箱已经存在

");

$(".btn").attr("disabled", true);

}

if(data==1)

{

$("#content").html("

$(".btn").attr("disabled", false);

}

if(data==13)

{

$("#content").html("

邮箱不能为空

");

$(".btn").attr("disabled", true);

}

}

});

});

});

后台数据处理：

@RequestMapping("check_email.do")

public void checkEmail(HttpServletRequest request, HttpServletResponse response) throws IOException {

PrintWriter out= response.getWriter();

String email= request.getParameter("email");

// 检查数据库是否重名

boolean exist = service.emailExist(email);

if (!exist) {

Servlets.writeHtml(response, "1");

} else {

Servlets.writeHtml(response, "2");

}

if(StringUtils.isBlank(email))

Servlets.writeHtml(response, "3");

out.close();

/*if (StringUtils.isBlank(email)) {

Servlets.writeHtml(response, "false");

return;

}

if (StringUtils.equals(email, original)) {

Servlets.writeHtml(response, "true");

return;

}

// 检查数据库是否重名

boolean exist = service.emailExist(email);

if (!exist) {

Servlets.writeHtml(response, "true");

} else {

Servlets.writeHtml(response, "false");

}*/

}

元生后台：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

response.setContentType("text/html:charset=utf-8");

response.setCharacterEncoding("utf-8");

PrintWriter out= response.getWriter();

request.setCharacterEncoding("utf-8");

String username= request.getParameter("username");

String password= request.getParameter("password");

if(username.equals("洪帆"))

{

/*out.println("

"+username+"

");*/

out.println("1");

/*out.println("

"+password+"

");

out.println("

"+"用户名准确"+"

");*/

}else{

out.print(username);

out.print("用户名或密码错误");

}

out.close();

}

jquery校验textarea必填

$("#sub1).click(function(){

var text1=$("#text1").val();

if(text1==""){

alert("不能为空!");

$("#text1").select();

$("#text1").focus();

}else{

$("#form1").submit();

}

})